To achieve speed in an optical coupler, the light source, such as a light emitting diode or LED, must be switched on and off rapidly. The driver described here provides rapid switching by generating several different, time-varying current components. The performance of the driver is enhanced by adding a pedestal current to the illuminating current for a period of time. Collectively, all of the applied currents help the LED to rapidly change from the xe2x80x9coffxe2x80x9d state to the xe2x80x9conxe2x80x9d state and back again.